High data-rate packet communications for cellular networks using CDMA: algorithms and performance

Abstract

Abstract-The advantages of code division multiple access (CDMA) for cellular voice have become well known, and IS-95-based systems have now been widely deployed. Attention is now focused on higher data-rate packet services for cellular systems. Although many packet multiple access schemes have been studied over the years, researchers have often studied single cell performance and ignored reuse. Moreover, direct sequence spread spectrum (DSSS) has been considered unsuitable for high data-rate packet multiple access since spreading limits the permitted data rates, DSSS requires large overhead (preambles) for acquisition and requires closed-loop power control.In this paper, we describe a scheme for high data-rate packet service using CDMA that addresses all of the above problems and has been standardized in Revision B of IS-95. A low rate fundamental code channel is maintained that eliminates the need for long preamble and provides closed-loop power control. Reuse is managed by the infrastructure through a "burst-level" admission control based on load and interference-level measurements at the base stations and mobiles.We report on the feasibility of such a burst-mode packet data service for cellular CDMA networks. The focus is not only on the performance of high data-rate users, but also on the impact on voice users sharing the CDMA band. We propose a multitiered performance analysis methodology consisting of a mix of static simulations, dynamic simulations at different time scales, and analytic methods to address the various feasibility issues: impact on coverage; capacity; power control; and effectiveness of burst admission algorithms. We expect that detailed performance work on all aspects discussed in this paper will continue in the future. However, based on the current study, we can conclude that the proposed approach is well suited for third-generation wideband CDMA systems being considered for standardization throughout the world.Index Terms-Burst admission, CDMA packet data, high datarate services, load and interference-based dynamic assignment (LIDA), wireless data.

Mobility and QoS-Aware Service Management for Cellular Networks

“…This is valid for forward services and reverse services that are not in soft handoff with other cells. However, for reverse connections that have, for instance, 2 soft handoff legs as in our simulations, this computing load would be multiplied by the number of handoff legs, which proves that soft handoff is computationally expensive as mentioned in (Kumar & Nanda, 1999).…”

“…As in (Kumar & Nanda, 1999), P j,K can be written as a function of SIR, i.e. the received ratio of signal bit energy to noise power spectral density (Eb/No) j,K for MS j in cell K divided by its processing gain G j ,…”

“…The MS reports pilot strength information for cells in its neighbour list in the Paging Channel. So, to avoid producing excessive interference at a neighbour cell NC, we constrain the path loss difference between the strongest active and strongest non-active pilots to a minimum ∆ (Kumar & Nanda, 1999) such that…”

The Study of Burst Admission Control in an Integrated Cellular System

“…Code Division Multiple Access (CDMA) has been a mainstream access technique in the third-generation mobile cellular system, [1] [2]. The CDMA techniques have been reported to offer attractions such as high link capacity, more efficient spectral utilization, soft capacity and anti-multipath shadow fading [3] [4].…”

“…In this paper, we fully investigated the performance of a CDMA system which supports the data users. In the proposed algorithm [1][2], data user's burst admission is permitted based on the load situation of the system. Performance measures obtained included the system capacity, ISR limitation and the constraint set between the load of the system and the allowed maximum data rate.…”